/*
 * Copyright (C) 2015 Jared Boone, ShareBrained Technology, Inc.
 *
 * This file is part of PortaPack.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2, or (at your option)
 * any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; see the file COPYING.  If not, write to
 * the Free Software Foundation, Inc., 51 Franklin Street,
 * Boston, MA 02110-1301, USA.
 */

#include <cstdint>
#include <cstddef>

#include <vector>
#include <memory>

#include "gpdma.hpp"

namespace lpc43xx {
namespace gpdma {
namespace lli {

enum class ChainType : uint8_t {
    Loop = 0,
    OneShot = 1,
};

enum class Interrupt : uint8_t {
    All = 0,
    Last = 1,
};

struct ChainConfig {
    ChainType type;
    size_t length;
    Interrupt interrupt;
};

enum class BurstSize : uint8_t {
    Transfer1 = 0,
    Transfer4 = 1,
    Transfer8 = 2,
    Transfer16 = 3,
    Transfer32 = 4,
    Transfer64 = 5,
    Transfer128 = 6,
    Transfer256 = 7,
};

enum class TransferWidth : uint8_t {
    Byte = 0,
    HalfWord = 1,
    Word = 2,
};

enum class Increment : uint8_t {
    No = 0,
    Yes = 1,
};

using PeripheralIndex = uint8_t;

struct Endpoint {
    PeripheralIndex peripheral;
    BurstSize burst_size;
    TransferWidth transfer_size;
    Increment increment;
};

struct ChannelConfig {
    ChainConfig chain;
    FlowControl flow_control;
    Endpoint source;
    Endpoint destination;

    constexpr gpdma::channel::Control control(
        const size_t transfer_size,
        const bool last) {
        return {
            .transfersize = transfer_size,
            .sbsize = toUType(source.burst_size),
            .dbsize = toUType(destination.burst_size),
            .swidth = toUType(source.transfer_size),
            .dwidth = toUType(destination.transfer_size),
            .s = source_endpoint_type(flow_control),
            .d = destination_endpoint_type(flow_control),
            .si = toUType(source.increment),
            .di = toUType(destination.increment),
            .prot1 = 0,
            .prot2 = 0,
            .prot3 = 0,
            .i = ((chain.interrupt == Interrupt::All) || last) ? 1U : 0U,
        };
    }

    constexpr gpdma::channel::Config config() {
        return {
            .e = 0,
            .srcperipheral = source.peripheral,
            .destperipheral = destination.peripheral,
            .flowcntrl = flow_control,
            .ie = 1,
            .itc = 1,
            .l = 0,
            .a = 0,
            .h = 0,
        };
    };
};

constexpr ChannelConfig channel_config_baseband_tx{
    {ChainType::Loop, 4, Interrupt::All},
    gpdma::FlowControl::MemoryToPeripheral_DMAControl,
    {0x00, BurstSize::Transfer1, TransferWidth::Word, Increment::Yes},
    {0x00, BurstSize::Transfer1, TransferWidth::Word, Increment::No},
};

constexpr ChannelConfig channel_config_baseband_rx{
    {ChainType::Loop, 4, Interrupt::All},
    gpdma::FlowControl::PeripheralToMemory_DMAControl,
    {0x00, BurstSize::Transfer1, TransferWidth::Word, Increment::No},
    {0x00, BurstSize::Transfer1, TransferWidth::Word, Increment::Yes},
};

constexpr ChannelConfig channel_config_audio_tx{
    {ChainType::Loop, 4, Interrupt::All},
    gpdma::FlowControl::MemoryToPeripheral_DMAControl,
    {0x0a, BurstSize::Transfer32, TransferWidth::Word, Increment::Yes},
    {0x0a, BurstSize::Transfer32, TransferWidth::Word, Increment::No},
};

constexpr ChannelConfig channel_config_audio_rx{
    {ChainType::Loop, 4, Interrupt::All},
    gpdma::FlowControl::PeripheralToMemory_DMAControl,
    {0x09, BurstSize::Transfer32, TransferWidth::Word, Increment::No},
    {0x09, BurstSize::Transfer32, TransferWidth::Word, Increment::Yes},
};

constexpr ChannelConfig channel_config_rssi{
    {ChainType::Loop, 4, Interrupt::All},
    gpdma::FlowControl::PeripheralToMemory_DMAControl,
    {0x0e, BurstSize::Transfer1, TransferWidth::Byte, Increment::No},
    {0x0e, BurstSize::Transfer1, TransferWidth::Word, Increment::Yes},
};

class Chain {
   public:
    using chain_t = std::vector<gpdma::channel::LLI>;
    using chain_p = std::unique_ptr<chain_t>;

    Chain(const ChannelConfig& cc)
        : chain(std::make_unique<chain_t>(cc.chain.length)) {
        set_lli_sequential(cc.chain_type);
        set_source_address()...
    }

   private:
    chain_p chain;

    void set_source_peripheral(void* const address) {
        set_source_address(address, 0);
    }

    void set_destination_peripheral(void* const address) {
        set_destination_address(address, 0);
    }

    void set_source_address(void* const address, const size_t increment) {
        size_t offset = 0;
        for (auto& item : *chain) {
            item.srcaddr = (uint32_t)address + offset;
            offset += increment;
        }
    }

    void set_destination_address(void* const address, const size_t increment) {
        size_t offset = 0;
        for (auto& item : *chain) {
            item.destaddr = (uint32_t)address + offset;
            offset += increment;
        }
    }

    void set_control(const gpdma::channel::Control control) {
        for (auto& item : *chain) {
            item.control = control;
        }
    }

    void set_lli_sequential(ChainType chain_type) {
        for (auto& item : *chain) {
            item.lli = lli_pointer(&item + 1);
        }
        if (chain_type == ChainType::Loop) {
            chain[chain->size() - 1].lli = lli_pointer(&chain[0]);
        } else {
            chain[chain->size() - 1].lli = lli_pointer(nullptr);
        }
    }

    gpdma::channel::LLIPointer lli_pointer(const void* lli) {
        return {
            .lm = 0,
            .r = 0,
            .lli = reinterpret_cast<uint32_t>(lli),
        };
    }
};

} /* namespace lli */
} /* namespace gpdma */
} /* namespace lpc43xx */
